Re: [Qemu-devel] 9pfs: unWRITAble dirs with random errors in guest

[Michael Tokarev]

[Subject corrected: the issue is about unWRITAble dirs, not unREADable ones]

28.02.2013 17:55, M. Mohan Kumar wrote:
> Michael Tokarev <address@hidden> writes:
> 
> Hi,
> 
> Please try mounting with -oversion=9p2000.L
> 
> With qemu-1.4.0 and 9p2000.L, I could not recreate this issue. ie not
> getting Unknown error during directory listing.

Yes, with 9p2000.L it works fine, both reported
issues are gone.

> I am using Guest kernel 3.8.0-rc5+.

But do you see my original error, with the default mount version?
(I'm using 3.2 guest kernel if that matters, and it is also 32bits,
which should not matter).

Thank you!

/mjt

>> When I mount a 9pfs filesystem in guest with no write permission for
>> some dirs, I'm getting strange errors in guest.
>>
>> Host (as a regular user):
>>  qemu-system-x86_64 -virtfs 
>> local,path=/,security_model=mapped-file,mount_tag=tag
>>
>> Guest:
>>  # mount -t 9p -o trans=virtio,ro tag /mnt
>>  # ls /mnt
>>  ls: reading directory /mnt: Unknown error 593
>>  # ls /mnt/dev
>>  ls: reading directory /mnt/dev: Unknown error 849
>>  # ls /mnt/tmp
>>  [works]
>>  # ls /mnt/root
>>  ls: cannot open directory /mnt/root: Permission denied
>>
>> So, it reports errors while trying to _read_ (not open)
>> readable but non-writable dirs, and these errors are _random_.
>> It correctly reports errors when trying to open an unreadable
>> dir.
>>
>> This is 1.4.0.  Similar problem exists with earlier versions
>> of qemu.
>>
>> Thanks!
>>
>> /mjt
>